Andrés O'Donnell (1886–?) was an agent of the Peruvian Amazon Company of Irish–Peruvian descent, employed in the Putumayo River basin between 1903 and 1910. He managed the Entre Rios station for the Company, which collected rubber from locally enslaved indigenous populations. In 1910 Roger Casement described his plantation as "merely a center of terrorization – that is all." O'Donnell is included in three different testimonial correspondences collected in Walter Ernest Hardenburg's 'The Putumayo: The Devil's Paradise,' and at least five testimonies collected by Roger Casement in 1910. Casement's report as well as Hardenburg's book were published in 1912, and helped to expose atrocities that occurred during the Putumayo genocide. An investigation carried out by judge Carlos A. Valcárcel later managed to collect at least twenty three depositions that incriminated O'Donnell in the Putumayo genocide. O'Donnell separated from the Company in 1910, and later disappeared without a trace in the United States around New York.

Early life There is very little public information written about Andrés O'Donnell's early life. What is documented about this time, comes from Roger Casement's journal as relayed by Andrés himself. "I miss a good deal of his Spanish. He says his grandfather went to Spain from Ireland, and father came from Spain to Peru. I doubt the grandfather. It is probably further back." Andrés was born in Peru around 1886, and left "Lucia" in 1901 near the age of 17. The name "Lucia" is not specified to be a settlement or a person in Casement's journal. Sometime within the next two years O’Donnell was able to secure employment with a rubber firm operating along the Putumayo River.

Career O'Donnell began working for Julio César Arana's rubber firm sometime between 1901 and 1903. This was when he was around the age of eighteen or twenty. By 1904, O'Donnell was managing the Entre Rios station, which was located near the upper Cahuinari River. During his time in the Putumayo, he learned a Huitoto language, and became a fluent speaker in it. Near the end of his employment, Entre Rios was estimated to have a "great clearing" of between 200 and 300 acres surrounding the buildings. During his management it was stated of him, that he compelled the natives to bring in a quota of rubber, and punished them when they didn't. More often than not this punishment included flogging, or the 'cepo' which was a stockade like device. The cepo at Entre Rios contained 24 holes for the feet or legs, and was noted to be larger than the cepo at Occidente or Ultimo Retiro.

When Andrés arrived to Entre Rios in 1903 there was an old great Native chief named Chingamuni, who still retained influence over the local Huitoto population. The manager at the time was Elías Martinengui, who only had one fabrico at the station before O'Donnell assumed management. O'Donnell mentioned that the chief was a "captain of energy and character" who was highly respected by the Huitoto's. On the way back with O'Donnell from La Chorrera after a fabrico, Chingamuni was killed during a quarrel by a Colombian named Calderon who also worked for Arana. O'Donnell stated that the Colombians were at Entre Rios and all over the Putumayo before he arrived. The Colombians "'treated' the Natives 'very badly,'" according to O'Donnell they were "much worse than he and the Peruvians... it was simply 'conquering' Indians and holding them as slaves – killing them and their women and living entirely on them." In Roger Casement's journal, he notes that this is exactly what O'Donnell and other agents of the Peruvian Amazon Company continue to do, "only with less killing."

A judicial investigation that occurred after O'Donnell's employment with the Company implicated him with the September 24, 1903 massacre of Ocaina natives at La Chorrera, ordered by Benjamin Larrañaga. This was witnessed by Emilio Mozambite and declared in his testimony. The years around 1905 are referred to as the "state of siege". Employees of the station were not allowed to bathe or wash their clothes without taking their rifle to the river and letting O'Donnell know. The "state of siege" took fruition in the Natives sending "pot shots" at the Company employee's in defiance and retaliation. According to O'Donnell he was also shot at while bathing by the river.

Early in his career O'Donnell was invited by four Andoques captains to visit their land. The captains said that they would give him rubber if he made the journey, however O'Donnell declined. Sometime after this, the Andoques and Guimaraes Natives rebelled. According to O'Donnell the Andoques threatened the Guimaraes with death if they did not help them against the whites. During this rebellion he was shot at on multiple occasions while at Entre Rios. O'Donnell never relayed to Roger Casement how the rebellion was suppressed. A map drawn in 1908 by O'Donnell depicted the "houses" of each Native tribe or "nation" around his section as well as the important paths and streams. The map had four crosses depicting where the Natives had apparently burned down "houses of the Colombians." Another area marked in red signified where he was ambushed by Natives a few miles from Entre Rios. This sketch map is still a part of the Casement Papers located at the National Library of Ireland.

According to the Entre Rios pay sheet, Andrés made 3 Peruvian soles per arobba, and 7% commission on the rubber his station collected. In 1910, O'Donnell apparently "earned" around 2000 Peruvian sols, which was around £200, every 'fabrico' from the rubber brought to Entre Rios. A 'fabrico' represented a quarter of a years worth of time, during the time of the year it was possible to harvest rubber. While O'Donnell stated he only required two fabricos per annum, and that represented around 16,000 kilos. With those numbers, that could equal a total of 33,000 kilos of rubber a year. Frederick Bishop states that was "scarcely the truth" when he was at Entre Rios last year, a fabrico came out to 24,000 kilos, and there were "nearer three than two fabricos in the year." Roger Casement estimated that if an average load for a fabrico equaled 30 kilos and brought in 16,000 kilos of rubber, this would require 5,333 natives, who were enslaved. According to Bishop "men often carry 40 or even 45 kilos down to Puerto Peruano." A journey on foot from Entre Rios to Puerto Peruano could take seven hours, and presumably longer with a heavy load of rubber. Roger Casement estimated the road from the port to Entre Rios to be between 12 and 14 miles in total, which was developed and maintained with an enormous effort from the Natives. Natives that lived further than Entre Rios of course had a longer walk, some Natives from the nearby Matanzas station had a total journey of 70 miles that had to be completed with a load of rubber. There are multiple mentions of starvation and malnourished Natives in Casement's journal on the way from Puerto Peruano to Entre Rios. O'Donnell also told Casement that when he arrived at Entire Rios in 1903 there were many more Natives, according to him a great number of them have died from small pox or other causes.

Casement noted that all the men at Entre Rios "except O'Donnell and Martin Arana, go barefooted and are dressed like 'beachcombers.' All have 'wives' and several of them children by these poor women. O'Donnell has a 'Harem' apart – a house like Velarde's in the compound." There were nine other men employed by the Company at Entre Rios, which does not account for the muchachos de confianza of the station. Casement thought the employment of this staff was a "very great waste here of the Company's money – or rather of the poor Indians money – for they supply all."

Entre Rios was the largest station owned by the Peruvian Amazon Company in its region. Other stations such as La China and Matanzas had to pass through Entre Rios on the road to Puerto Peruano. During the last fabrico of 1910 and Casement's investigation, the manager of Matanzas, Armando Normand, and his enslaved Native workers had to pass through Entre Rios to get to Puerto Peruano. O'Donnell mentioned to Casement that they "were not good friends and had not held any intercourse for six months." This conversation took place after the two witnessed Normand trying to avoid the Entre Rios road and Casement's attention. The volunteered self explanation that later came from Normand was that he was avoiding O'Donnell's crop fields since the Matanza's Natives constantly stole food from there.

Andrés O'Donnell was still working for the Peruvian Amazon Company by the time Roger Casement left the Putumayo in November 1910. Sometime over the next four months O'Donnell separated from the Company, and left the Putumayo region. In August 1911, Casement discovered Andrés was "living the life of Riley" in Barbados. Apparently Julio Arana still owed O'Donnell a decent amount of money. However he had no way of getting that money back.

Role in the Putumayo genocide During O'Donnell's management of the Entre Rios station, multiple Huitoto and Bora tribes were enslaved and induced to extract rubber for the Company. Some of these nations include the Timenses, Muitrifos, Mintofigis, Guarmaraes, Inoikoma, Muinanes, and Mimames among a number of other tribes. According to a judicial investigation, O'Donnell killed off the Native women of the Entre Rios section if they were discovered to have venereal diseases. O'Donnell, as well as other people told Casement about several cases of the Native "captains" who were boys. Some of these young boys were around the age of fifteen and came to inherit the hereditary role when the previous captain was killed.

Depositions that were collected by Hardenburg relating to O'Donnell include Daniel Collantes; Marcial Gorries; and Juan Rosas. Daniel Collantes gave a long testimony of crimes in the Putumayo, and mentioned O'Donnell in passing regarding an incident that happened with Elias Martinengui. In the conclusion of Collantes statement, Daniel gives a list of names he refers to as diabolical criminals including Andrés O'Donnell and other managers who worked for Arana. Marcial Gorries wrote a letter to Benjamin Saldaña Rocca, which was published by La Felpa on January 5 and 12, 1908. The letter stated the "principal criminals" are the Chiefs of Sections, and lists of names including Armando Normand; José Inocente Fonseca, Augusto Jiménez Seminario, Andrés O'Donnell and six others. Marcial continued "With the exception of O'Donnell who has not killed Indians with his own hands, but has ordered over 500 Indians to be killed, all the rest – every one of them – have killed with their own hands." In Juan Rosas deposition, he states that O'Donnell induces the Natives to deliver a quota of rubber to him, and when they do not "he submits them to most cruel punishments, mutilating them and then ending by murdering them."

An investigatory commission was sent by the Peruvian Amazon Company in 1910, which the British Foreign office attached Roger Casement to learn about the treatment of Barbadians in the Putumayo. They travelled through Puerto Peruano to Entre Rios in October. The Barbadians who made depositions to Roger Casement and mentioned their time working for Andrés O'Donnell include Frederick Bishop, James Chase, Allan Davis, Joseph Minggs, Augustus Walcott, and Sidney Morris.